SPRING LAKE
TOWNSHIP, Mich. (AP) — More than one in five Great Lakes beach closing
orders based on bacteria concerns may be unnecessary, according to a
University of Michigan researcher who is testing that idea this summer.

David Rockwell
of the university's School of Natural Resources and Environment is using a
$140,000 U.S. Environmental Protection Agency grant to study the
relationship between E. coli test results and actual health risk to
swimmers.

The project is a
collaboration of Michigan and the National Oceanic and Atmospheric
Administration's Great Lakes Environmental Research Laboratory in Ann Arbor.

"My estimate is
that 23 percent of the time that swimming is prohibited at Great Lakes
beaches due to high bacteria levels, those decisions are actually mistakes,"
said Rockwell. He is beach water quality forecasting coordinator at the
Cooperative Institute for Limnology and Ecosystems Research, a collaboration
between the university and the National Oceanic and Atmospheric
Administration.

Swimming
advisories or closures were posted at Great Lakes beaches on 3,136 days in
2010, according to the university. Most often, authorities issue advisories
and swimming closures after heavy rainstorms wash bacteria-contaminated
water into lakes.

"This new tool
helps us make better beach-management decisions so we can get the situation
called correctly," Rockwell said in a statement Monday. He said early
testing of the Forecast Decision Support System showed that it was more
accurate than current beach-monitoring techniques about 70 percent of the
time.

The new
forecasting tool is being extensively tested at five Michigan beaches, said
university spokesman Jim Erickson.

"Using equations
generated by the forecast tool, water-quality forecasts for the five beaches
are issued four times a day by the National Weather Service," Erickson said.
"After the swimming season closes, those forecasts will be compared with
actual bacterial levels in water samples collected at the beaches throughout
the summer to determine the system's accuracy."

The standard
beach monitoring method is based on lab tests for E. coli colonies from
water samples, which can take up to 24 hours to complete. That means
advisories can be issued after the danger has passed.

One site for the
water-quality forecasts is North Beach Park in Ottawa County's Spring Lake
Township, near Grand Haven. The others are Grand Haven State Park Beach in
Ottawa County, Bay County State Recreation Area Beach in Bay County, and
Memorial and Metro beaches in Macomb County.